Planar nanofluidic channels are powerful tools for the investigating of materials under confinement such as confined water, DNA and proteins. The channels are also essential components in nanofluidic systems.
Some materials naturally include nanochannels or a random network of pores. For example, carbon nanotubes, zeolites and polymers such as poly(vinyl methyl ether) (PVME) and polyvinylpyrrolidone (PVP) have nanochannels. However, many limitations with utilizing nanochannels in these materials exists, such as their randomness, the difficulty of controlling and modifying their pore surfaces uniformly and consistently, the difficulty of studying the effects of external electric fields, and the occurrence of parasitic signals that obscure test readings.
Various methods such as wet-etch and dry-etch of silicon and silicon dioxide thin films have been developed for the fabrication of nanochannels from about 20 nm to 100 nm. For example, techniques developed from traditional semiconductor processing such as patterning, thin film deposition, etching and wafer bonding have produced nanochannels from about 20 nm to 100 nm, mainly for nanofluidic research and bio-molecule separation and detection investigations.
Unfortunately, difficulties in producing nanofluidic channels having a height of from about 1 nm to about 10 nm remain. Channels having a height from about 1 nm to about 10 nm would be useful for many scientific and engineering investigations, including confinement effect research, tribology studies and biology studies. For example, nanofluidic channels have been used with dielectric spectrometers to measure the effects of an electric field on a liquid or gas. Dielectric spectrometers probe the interactions between a time-dependent electric field and molecules that are polarized and/or charged. The ability to form nanofluidic channels of a smaller height could greatly improve such devices.
Dielectric spectrometers having nanofluidic channels can be used to detect and analyze biological molecules, cells, their dynamic processes and surface interactions, such as protein and DNA analysis (including DNA folding-unfolding process analysis), cell detection and analysis, molecular structure analysis, and bimolecular surface interactions; analyze the dynamics of glass-forming liquids (such as glycerol) and supercooled liquids (compared with other experimental instruments, dielectric spectroscopy is proving to be an ideal tool to study the relaxation processes of these materials); study the molecular dynamics of polymers; in-situ sensing and monitoring; and investigate molecular dynamics in confined spaces. Examples of confined liquids include biological water between two membranes and liquid lubricants between two friction surfaces. Since both are only a few molecules thick, dielectric spectroscopy with nanofluidic channels enables the study of the dynamic interactions between surfaces and confined liquids.
While various methods for fabricating planar nanofluidic channels have been developed, room for improvement in the art exists.